Emergency A Street Slide, Between Cresent Ave and North 6th Street, in Castro Valley, Alameda County.
The Alameda County Public Works Agency owns and maintains A Street Road in Castro Valley. Due to the 2022-2023 winter storm and high run off of flows, a retaining wall located on the eastbound side of A Street at the boundary between Unincorporated Castro Valley and adjacent to San Lorenzo creek failed. Consequently, the sidewalk and a section of the roadway washed out into the creek. Since then, the damaged portion of A Street has been closed to the eastbound traffic. As a result, emergency temporary repairs are being proposed to fix the road in order to open the street for vehicle traffic and to prevent the road from continuing to erode and collapsing into the creek. The temporary emergency repairs at A Street consist of the removal of the damaged retaining wall debris from the creek banks followed by the installation of approximately a 200 foot-long area by using sheet pile to stabilize the bank, then backfill the sheet piling with virgin Class 2 AB fill material, temporary install rock-filled supersack along the creek banks to prevent further erosion and reconnect storm drains with HDPE pipes. This will be followed by the reconstruction of the roadway with aggregate base grading and asphalt concrete paving.